Transmission



Sepe 24, 1946.' i P. om "2,408,336-

TRANsMIssoN Filed Jan. a, '1945 Patented Sept. 24, 1946 Palmer Orr,Muncie, Ind., assignor to Borg- Warner Corporation, Chicago, Ill., acorporartion of Illinois Application January 8, 1943, Ser-iaiNar/171,666

for use between the propellerand'engineof an aeroplane, and moreparticularly,v my invention relates to lubricating systern'sforsuchztransmissions.

Transmissions of the planetary'type Ahave been proposed for .useVbetween the engine and Spropelle'rfof aeroplanes One such transmissioncomprises a ring gear; -a sungear, planetl gears in mesh with the ringand sun gearsV and a carrier for the planet gears, and the transmissionis commonly yconnected with its ring .gear driven by the engine crankshaft, with the carrier connected to drive the propeller, and with thesun gear of the vitiansrnission held stationary.

i. It is an object ofV my invention to provide, in a transmission'ofthistype, an improved system forv lubricating the teeth ofA the gearsand also the bearingsbetweenthe fplanetrgears and the carrier for theplanet gears.V

More particularly it is an object of myinvention to provide such animproved lubricating sys- Vtern comprising an annular pressure chamberAwhich is in communication with a source of lubricant and with thebearings of the planet gears on the'planet gear carrier and whichrotateswith the gear carrier whereby lubricant is forced into the bearings dueto centrifugal force acting on the lubricant in the pressure chamber. Itisanother object to provide means for forcing the lubricant into thepressure chamber whereby the bearings for the planet gearsare'lubricated by ,lubricant under pressure due to centrifugal force andalso to the said means, o

It is another object to so construct the transmission that the annularpressure chamber is formed by the planet gear carrier and an annularmember fixed with respect to the carrier. It is contemplated that theannular member shall preferably be of sheet material in order to addlittle to the weight of the transmission.

It is still another object to pro-vide a passage claims. (o1. iai-6) iMy invention rentes ioiraiismission suitable Y tions, arrangements anddevices to be hereinafter Y described and claimed for carrying out theabove stated objects and-such other objects as will appeary from thefollowing description of a certain preferred embodiment illustrated inthe accompanying drawing.

Referring now to the drawing, the illustrated tiansmissionr comprises ahousing Iii in which is journaled a shaft Il by means of a bearing i2.The shaft i i is adapted tc'have fixed thereon,v to the left of thebearing I2, as seen in theV drawing,

anmaeroplane.propeller (not shown), and the shaft has splined thereon acarrier'or support member i3 in which is disposed a plurality of shaftsiii (one being shown .inthe drawing). A pin is is provided for iixingeach of the shafts ibi with respect to the member i3. A planet gear Iiiis rotatably disposedron-each of the shafts I4 by means of rollers Ii.Yi sun gear i8V is provided ccaxiaily disposed with respect to the shaftii and in mesh with the planet gears i. The gear i8 is spiined in anannular member it which is Vbolted to the housing Ii)l and which thusholds the sun gear I6 stationary and in position. A ring gear 25a-is ininesh with the planet pinions IG andis splined on amember 2i which isadapted to be connected to and carried rby the crank shaft of anaeroplane engine (not shown). It

Vwill be understood that the crank shaft functio-ns to hold the memberZI and the ring gear Zi in their position relative to the planet gearsflas shown in the drawing. Y

VThe shaft il, which is adapted to carry an aeroplane propeller,functions to drive the propeller at a slower speed than the member 2land 'ring gear 2i! are driven, as by the crank shaft of an aeroplaneengine. The ring gear 20 rotates while the sun gear It is stationary,and the planet gears I@ are thus caused to rotate about the sun gear I8,and they drive the carrier'member I3 and thereby the shaft il at somespeed slower than in the planet gear carrier irl-communication with thepressure chamber for directing a stream of lubricant on the meshingteeth of each of the vpla-net gears .and one of thegears inmesh with theplanet gears.

l fit is a further object to provide a passage between the lubricantpressure chamber and each of the bearings forthe planety gears which hasa perforated member therein, with the perforation being smaller than thecross-sectional area of the passage for limiting the iiow of lubricantinto the passage.

'The invention consists` ofthe novel' constructhat o-f the ring member29.

The lubricating system for the transmission comprises a central passage22eXtending into the shaft IIfrom ther end of the shaitwhich is adaptedtc be adjacent the engine for driving the vtransmission and radially,extending passages 23 V(one1being shown in the drawing) in the shaft.r

The carrier member I3 is formed with aplurality of passages E@ (onebeing shownin the drawing) each of which is inV communication with oneof the passages 23 in the shaft Ii. The carrier member I3 isiorrned withother passages 25 (one being shown 1in the drawing) each of which isr-disposed'so vas to directiiuid passing Vtherethrough from the rightside of the carrierx as shown in the ligure, on to the meshed teeth ofone of the planet gears It and the sun gear I8. Each of the shafts lilis provided with a central passage 26 therein extending into the shaftfrom the ,right end of the shaft, as seen in the figure, and each shaftis also provided with a passage 2l' which is in communication with thepassage 2t and is disposed to direct any fluid passing through thepassage 2l from the passage 26 on to the rollers il. The passage 26 ineach of the shafts lll is preferably provided with a perforated cup 28in its open end for forming a constricted opening for the passage.

A stamped annular sheet metal plate member 29 is provided on the rightside of the carrier member l as seen in the gure, and the plate member2Q is xed with respect to the carrier member E3 by means of a threadedcollar 30 on shaft Il and screws 3| in the carrier member. 20 The platemember 29 functions with the carrier member i3 to provide an annular,fluid-tight container or reservoir 32 at the right side of the carriermember i3 which reservoir is in communication with the passages 24 and25 in the carrier member and with the passages 26 in the shafts le.

The passage 22 is connected with a lubricant source (not shown), andwhen the gear carrier i3 is rotating, lubricant flows from the passage22, through the passages 23 and 2 and into the reservoir 32 on the rightside of the lplanet carrier i3. The oil ows from the fluid containerthrough the oil cups 2B and into the passages 26 and 2 in the shafts andon to the rollers Il, and the rollers are thereby lubricated. Oil alsoflows from the reservoir 32' through the passages 25 in the carrier i3and is directed thereby on to the meshed teeth of each of the planetgears i6 and the sun gear i3. The meshed teeth of the planet gears iiiand the ring gear 20 are lubricated by means of oil which has passed`from the passages 25 on to the teeth of the planet gears and which iscarried on the teeth of the latter gears as they rotate. This flow oflubricant to the rollers Il and gear teeth is due to the centrifugalforce on the lubricant in the reservoir 32 caused by the rotation of thereservoir. The reservoir thus acts as a lubricant pressure chamber andas a pump for lubricating the parts of the transmission. Although thereservoir 32 acts as a pump, in order to obtain a greater flow oflubricant, the lubricant is preferably forced into the passage 22 bymeans of a pump (not shown) driven by the aeroplane engine. Thelubricant iiowing through the passages 25 and 26 to lubricate the meshedteeth of the gears it and i8 and the rollers Vi respectively is drainedfrom the housing I3 to any suitable sump (not shown) by means of achannel 33 provided in the housing.

rThe perforated caps 2S function to effectively decrease thecross-sectional size of the lubricant conduits between the reservoir 32and rollers l'l, including the passages 26 and 2l, to the size of theperforations in the caps. The larger passages 2'5 are preferablyprovided instead of ones the size of the openings in the caps 23, as itis easier to drill the passages of larger diameter, and the carrier i3is thereby made lighter in weight. rIhe openings in the caps 28 and theopenings 25 are of such relative cross-sectional sizes that both therollers l'l and the meshed teeth of the gears I6 and I8 are effectivelylubricated, with the meshed teeth being lubricated 4 by a stream oflubricant passing through the openings 25 and forcibly impinging on themeshed teeth. The total elective cross-sectional area of the outlets ofthe reservoir 32 is less than the total cross-sectional area of theinlets of the reservoir; that is to say, the sum of the cross-sectionalareas of the passages 25 plus the sum of the effective cross-sectionalareas of the conduits to the rollers I'I from the reservoir is l0 lessthan the sum of the cross-sectional areas of the passage 2li, andlubricant under pressure is thus always maintained in the reservoir 32when the transmission is in operation.

The planetary gearing of the illustrated transmission is well lubricatedby means of the lubrication system shown and described. The provision ofthe system advantageously adds little to the cost of the transmission asa whole and adds little to the weight of the transmission.

I do not intend to limit the invention to the details shown anddescribed, except only insofor as certain of the appended claims arespecifically so limited, as it will be obvious that modifications may bemade without departing from the principles of the invention.

I claim:

1. In power transmission mechanism, the combination of a hollowrotatable shaft; a plurality of power transmitting elements; a supporton said shaft for rotatably mounting said elements about the axis ofsaid shaft; a source of lubricant under pressure discharging into saidshaft; an annular pressure chamber sealed wholly upon and rotatable withsaid support; inlet conduits for said chamber communicating with saidshaft; and discharge conduits connecting said chamber to said powertransmitting elements, the sum of the effective cross-sectional areas ofthe inlet conduits exceeding the sum of the effective cross- 40sectional areas of the'discharge conduits, whereby lubricantunderpressure is maintained in said chamber at all times.

2. In power transmission mechanism, a hollow rotatable shaft; a supporthaving a hub porton and a peripheral portion joined thereto; a pluralityof power transmitting members rotatably mounted on said support andarranged radially around the axis of said sup-port and hub; an an# nularmember assembled with the hub and peripheral portions of said supportand having an intermediate portion in spaced relation to said support,said annular member being constructed and arranged to constitute withsaid support a uid pressure chamber upon the side of said supportopposite said power transmitting members; and a source of lubricantunder pressure communicating with said shaft, said hub and shaft beingformed with passageways therein communicating with the hollow portion ofsaid shaft and said pressure chamber, and said support being formed withpassageways therein adjacent said power transmitting members fortransmitting lubricant from said pressure chamber to said powertransmitting members.

3. In power transmission mechanism, a hollow rotatable shaft; a supporthaving a hub portion and a peripheral portion jointed thereto; aplurality of power transmitting members rotatably mounted on saidsupport and arranged radially around the axis of said support and hub;an annular member assembled with the hub and peripheral portions of saidsupport and having anintermediate portion in spaced relation to saidsupport, the inner and outer margins of said annular member having fluidtight relationship sure chamber to said power transmitting members,

4. In a power transmission mechanism, the combination of a plurality ofgears, a support for said gears for mounting them for rotation about acentral axis, each of said gears also being rotatable about its ownbearing, which bearings are carried by said support, a gear in mesh withsaid first-named gears, a source of lubricant, an annular member securedto said support to form therewith a fluid-tight lubricant chamber, saidchamber being in communication with the source of lubricant, passagewaysthrough said support and communicating with said chamber for directinglubricant upon the meshed gears, and

other passageways in said support for connecting said chamber and saidbearings.

5. In a power transmission mechanism, the combination of a plurality ofgears, a support for said gears for mounting them for rotation about acentral axis, each of said gears also being rotatable about its ownbearings, which bearings are carried by said support, a gear in meshwith said first-named gears, a source of lubricant under pressure, anannular member secured to said support to form therewithA a duid-tightlubricant chamber, said support being provided with outlet passagewaysfor connecting the chamber with said bearings and with inlet passagewaysfor conr necting the chamber with said lubricant source,

said support being also provided with outlet passageways incommunication with said chamber for directing lubricant on the meshedteeth of said nrst and said second-named gears, the sum of the effectivecross-sectional areas of said inlet passageways being greater than thesum ofthe effective cross-sectional areas of said outlet passagewayswhereby lubricant under pressure is maintained lin said chamber at alltimes.

PALMER ORR.

